Process for the manufacture of a substance resembling natural rubber.



OFEIQEQ 'nunorrwnrssennnnn Ann Komtnn' KELLER, or 'nnrsisunc-msinnnicn, snruuaur,

. I mnrnnnlomenmvtanr.

assrenons T GESELLSGH-AFT run rn'nnvnnwnn rnnem. 13,11, AOIKDUISBURG- r'nocsss ron THE mn vvracrunn' or A sunsrancn nnsnmsnmo NATURALJBUBBER.

igcs'aio'n No Drawing.

To all whom it may concern.

Be it known that we, Runorr WEIsso'na 1 BER, a subjectof the German Em eror, re-

siding at No. 5 Varzinerstrasse, u-isburg- Meiderich, Germany, and Kama-an KELLER,

a subject of the German Em eror, residing at No.23 Quadtstrasse, Du1sburg-Meiderich, Germany, have invented certain new and useful Improvements in the Process for the Manufacture of a Substance Resembling Natural Rubber, of which the following is a specification.

- The processes hitherto known for the production of synthetic rubber or substances resembling natural rubber have all consisted in the polymerization 'by suitable means of 1.3-butadiene or isoprene or other hydrocarbon derivative of butadiene as such. In some cases it has been proposed to carry out those processes by mixing the materials with volatile hydrocarbons, for instance, benzol, but in such cases chemically neutral nonpolymerizable diluents have always been employed, and as a matter of fact it is clear from the latest literature (Ann. 0?. Chem. 383.(1911) pages 164, 182, 207) that special importance is placed upon the purity of the raw materials in the manufacture of artificial rubber.

The present inventors have now discovered that contrary to expectation a mixture of non-saturated hydrocarbons, such as can be obtained undervarious conditions from the distillation products of coal, can be converted for its greater part 'by the action of sodium into a rubber-like substance, while the other hydrocarbons either do not undergo any change or also form easily separable metallic compounds with sodium. Such mixtures can be separated by fractional distillation from the crude benzol (that is the first runnings of benzol obtained in the distillation of coal tar or irectly in the manufacture of coke. Such a material may be produced by compressin the gaseous products and vapors obtaine by the distillation of coal or the like or by refrigeratingsuch products or by both compressing and refrigerating such products. Both products are supposed to contain 1.3-butadiene, ac-

cording to statements in the literature of i s ecificationbf reassess j Pgt i td Jun}; '2, 1914,

. .ApplicatioufiledAugustS, i912, SerialNo.714,109.v

i to which the formation of rubber is probably due, that product contains hydrocar- 'bons -w1thtriplelinking, as well as cyclopentadiene which hasbeen recognizedas being-a cyclic non-saturated hydrocarbon by Kraemer and Spilker. (Ber; 03. Deutsch. Chem. Gee. 29, 552, 1896); and it contains also hydrocarbons of non-saturated character and unknown constitution. ()f these bydrocarbons accompanying butadiene it was not known hitherto how they would behave toward sodium under the conditions of the present invention. More particularly there was no reason for supposing that in the complicated mixture of these non-saturated hydrocarbons (of which, for instance cyclopentadiene shows the conjugated double linkings requisite for the formation of rubber), butadiene would be the only substance which would undergo conversion into a substance resembling rubber, without the formation of the latter being interfered with by the behavior of the concomitant substances. v

Example: The first runnings of crude benzol which have previously been freed from carbon disulfid by known methods, are subjected to fractional distillation which is continued with the employment of a condenser temperature of at least -1O degrees centigrade, until the vapors that pass over show a temperature of 25 degrees G. Then 100 parts of the distillate are mixed with 2 parts of sodium preferably used in the form of Wire or strip, and left to itself at the temperature of the atmosphere. After a short time the sodium compounds of the acetylene hydrocarbons separate out in the form of a white to yellowish brown powder which readily settles, whereupon-the polymerization of the remaining hydrocarbons begins, and finally the contents of the vessel are coir verted into a jelly-like mass. When no further thickening of this mass takes place the whole is diluted with benzol, the so ium compounds are removed by decantation or filtration, and the rubber is precipitated from the benzol solution by means of alco hol. The presence of small quantities of ammonia accelerates the polymerization.

Having now described our invention what we claim as new and desire to secure by Letters Patent is 1. A process for the manufacture of a sub till stance resemblin'g natural fubbrgfivhi'ch-donsists in subjecting .;a 2 fraction .of. :fthe- .ifir's't runnin'gsyrof: fa hydrocarbon of the =benz01 type taken 11p *to' 25. degrees Centigrade, free from tcarbondisirlfid, to: the z'acti'o'n of: isodium'.

2. iA process iorthe manufacturetof :5; sub 1 stancetresemblingnatural'1'ubber;which c0n+ sis't's in subjecting 121 -fraction oflith first.

runningsegof; 'be'nzol taken up to 25..degrees action of isodiiim;

3. A process-"for. themanilfzictureofza sub stance: resembling naturalrubbergzwhich 0011+:

'sists" in subjectingue fractionv of "the *fir'strunnin' rofva hydrocarbon of fthe -benzol' type ta en 'up :to e251 degreeszcentigradq free frbm carbon :dis'ulfi'd 'to theaction of sodium the presence of a small quantity of ammomaz.

4.-1A process for. the manufacture of a substance resembling natural rubber,rwhich 0011- sistsdrihubjectirig a fraction of the first 

